Pipes and tubular conduits – With closures and plugs
Reexamination Certificate
2001-01-09
2001-09-11
Brinson, Patrick (Department: 3752)
Pipes and tubular conduits
With closures and plugs
C138S090000, C220S315000, C220S323000
Reexamination Certificate
active
06286553
ABSTRACT:
REFERENCE TO MICROFICHE APPENDIX
This application is not related to any microfiche appendix.
BACKGROUND OF THE INVENTION
It is frequently necessary to close an opening in a tubular member either permanently or semi-permanently, that is, to close an opening where a valve is not required or is not desirable. One example of a semi-permanent closure arises when a hot tap is made into a pipeline or a vessel through a fitting connected to the pipeline or vessel. In the typical hot tapping application as utilized in the petroleum industry, a fitting usually in the form of a flange is welded on the exterior of a pipe that has flowing gas or liquid under pressure. A valve is then secured to the flange and a hot tapping machine secured to the valve. By use of highly specialized equipment, a hole can then be drilled through the wall of the pipe while a gas or liquid continues to flow through it to provide access to the interior of the pipe, such as for inserting equipment to temporarily block flow through the pipe while repairs are being made. After the repairs are complete the equipment is removed but the opening that provides communication to the interior of the pipe needs to be closed. Preferably the closure is made in such a way that at some future date access can be again obtained through the fitting to the interior of the pipe. This is just one example of the need for a closure for an opening in a tubular member.
For background information relating to closure devices, reference may be had to the following United States patents:
U.S. PAT. NO.
INVENTOR
TITLE
2,010,200
Reufener et al.
Sealing Device for Pressure
Containers
2,281,145
Duey
Pipe Plug
2,287,750
Clayton
Fill Pipe Cap
2,431,778
Sosaya
Test Cap
2,512,041
Steele
Temporary Drainpipe Closure
3,114,528
Forest
Base and Lock Assembly for
Pipe
3,155,116
Ver Nooy
Apparatus for Closing Side
Openings into Pipelines
3,179,446
Paterson
Extension Fitting Having
Initial Flexible Lip Seal
Gasket
3,483,894
Finocchiaro
High Pressure Pipe Test Plug
3,765,456
Karpenko
Chemical Cleaning Line
Connector
3,766,947
Osburn
Fluid Tight Closure
4,377,185
Katz
Hydrotest Apparatus
4,387,740
Vanzant
Cam-Flange
4,466,550
Sullivan
Closure for a Cylindrical
Opening Having Improved
Venting Means
4,576,778
Ferree et al.
Core Barrel Plug
4,609,209
Ralls
Precise Alignment Adapter
Flange
4,693,278
Wilson et al.
Safety Closure Member
4,902,043
Zillig et al.
Fluid Coupling and Seal
Assembly
5,035,266
Benson et at.
Mechanical Plug for Clean-
Out Tees
5,038,830
Arnaud
Pipe and Sealing Device
5,437,309
Timmons
Lockable Well Cap
5,450,765
Stover
Apparatus for Providing
Signal Communication
Between the Interior and
Exterior of a Pipeline
5,975,142
Wilson
Removable Closure System
BRIEF SUMMARY OF THE INVENTION
This invention provides a removable closure including a tubular member having a cylindrical opening for the passage of tools or for flow of liquids or gases. In a typical application of the invention the closure may be in the form of a flange member, that is, a tubular member that has an integral radially extending flange portion that is readily adaptable for the attachment of other structural or piping devices. The tubular member has an inner end and an outer end and an internal passageway that is defined by a first cylindrical surface of a first internal diameter adjacent the inner end and a second cylindrical surface of a larger internal diameter adjacent the outer end, the difference in internal diameters providing a circumferential ledge. The tubular member second cylindrical surface has an increased internal diameter circumferential slot therein that is spaced from the circumferential ledge.
A cylindrical plug is positioned within the tubular member. The plug has an external diameter greater than the diameter of the tubular member first cylindrical surface and slightly less than the diameter of the second cylindrical surface. The cylindrical plug is thereby telescopically positionable within the tubular member second internal cylindrical surface and in engagement with the circumferential ledge.
An expandable snap ring is secured to an upper surface of the cylindrical plug and has a collapsed and an expanded condition. When in the collapsed condition the snap ring has an external cylindrical diameter less than the diameter of the tubular member second internal cylindrical surface. In its expanded condition, the snap ring fits into the tubular member circumferential slot so that the cylindrical plug is captured between the circumferential ledge and the snap ring.
A link plate is supported on the cylindrical plug and in a plane of the snap ring and within the snap ring. The snap ring has a gap therein providing snap ring opposed outer ends. Links extending from the link plate to the snap ring outer ends serve to expand the snap ring when the link plate is moved radially outwardly and to contract the external dimension of the snap ring when the link plate is moved radially inwardly.
A cam is utilized to radially inwardly or outwardly displace the link plate and thereby expand or contract the outer circumferential dimension of the snap ring to move it positively into or out of the circumferential slot in the tubular member.
When the link plate is in its outer position and the snap ring within the circumferential slot, a keeper in the form of a bolt may be threaded through the link plate and into the top surface of the plug so that the snap ring is positively retained in its outward most position to retain the plug in position within the tubular member.
In a second embodiment the snap ring is formed of a first and a second leaf portion. Each leaf portion having an outer end and an inner end. Each leaf portion is hinged to the plug body adjacent the leaf portion inner end. A linkage mechanism is secured to the outer end of each of the leaf portions. By actuation of the linage mechanism in one direction the leaf portions are moved radially outwardly with respect to each other to extend within the tubular member circumferential slot to lock the cylindrical plug within the tubular member. By actuation of the linkage mechanism in an opposite direction the leaf portions are moved radially inwardly with respect to each other to withdraw the leaf portions from the tubular member circumferential slot to permit the plug member to be removed from within the tubular member.
A better understanding of the invention will be obtained from the following description of the preferred embodiments and the claims, taken in conjunction with the attached drawings.
REFERENCES:
patent: 2010200 (1935-08-01), Rufener et al.
patent: 2281145 (1942-04-01), Duey
patent: 2287750 (1942-06-01), Clayton
patent: 2431778 (1947-12-01), Sosaya
patent: 2512041 (1950-06-01), Steele
patent: 3114528 (1963-12-01), Forest
patent: 3155116 (1964-11-01), Ver Nooy
patent: 3179446 (1965-04-01), Paterson
patent: 3483894 (1969-12-01), Finocchiaro
patent: 3765456 (1973-10-01), Karpenko
patent: 3766947 (1973-10-01), Osburn
patent: 4377185 (1983-03-01), Katz
patent: 4387740 (1983-06-01), Vanzant
patent: 4466550 (1984-08-01), Sullivan
patent: 4576778 (1986-03-01), Ferree et al.
patent: 4609209 (1986-09-01), Ralls
patent: 4693278 (1987-09-01), Wilson et al.
patent: 4775074 (1988-10-01), Ershig
patent: 4902043 (1990-02-01), Zillig et al.
patent: 5035266 (1991-07-01), Benson et al.
patent: 5038830 (1991-08-01), Arnaud
patent: 5127535 (1992-07-01), Shinno
patent: 5437309 (1995-08-01), Timmons
patent: 5450765 (1995-09-01), Stover
patent: 5975142 (1999-11-01), Wilson
Brinson Patrick
Head Johnson & Kachigian
TDW Delaware Inc.
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